1. Field of the Invention
The present invention relates to a road data specification method, a road data editing method, a map data editing apparatus, a map data editing system, a storage medium which stores a software program for specifying road data, and a storage medium which stores a software program for editing road data.
2. Description of Related Art
The Dijkstra method in a car-navigation system and Japanese Patent Laid-Open No. Hei 1(1989)-260628, are examples of art where a shortest route between two points is found, and the search result is displayed in superimposed form on a map display.
Other art is known, in which information of traffic congestion on a road is acquired by a radio communication, or infrared-ray communication, a telephone or the like, and speed information relative to the road is updated.
A traveler often desires to navigate an optimal route from a geographical starting point to a geographical ending or terminal point by making use of road data containing road speed information and classification information indicating whether a road to be navigated is a general road or a superhighway. However, a specific road is always congested, so that a car cannot run at the speed limit of the road, and a point where traffic accidents frequently happen may exist. In this case, a traveling road user may not wish to drive through the point, and may wish to update the road attribute data items (road speed, distance, risk and the like) by specifying a specific block of a road. Also, in some cases, a user may wish to change road attribute data items for a predetermined range adjacent to a predetermined block of a road when the update of the road attribute data items for the specific block of the road is requested.